This invention relates generally to wrist instruments with analog hands driven by a stepping motor and gear train and carrying out timekeeping as well as other functions. More particularly, the invention relates to a universal stepping motor/gear train module for use in a combined function wrist instrument.
Electronic wristwatches are well known which have analog hands driven by a stepping motor through a speed reducing gear train. Such watches always include as part of the movement a printed circuit board which serves as a mounting platform and interconnects necessary electrical components including an integrated circuit, quartz crystal, and various discrete components such as transistors and capacitors. The movements also generally include provision for insertion of a button-type energy cell and spring contact switches which are connected to terminals on the circuit board.
It has also been proposed that quartz analog watches include provision for digital timekeeping and to include a digital opto-electric display in combination with the analog hand display, this being sometimes called a "combo" watch. An example of a combo watch is seen in U.S. Pat. No. 4,236,240 in which stepping motor and gear train are assembled at an eight o'clock location in a recess of a support frame, and wherein a circuit board is disposed elsewhere in the movement in the same plane with liquid crystal display on side and an energy cell on the other. The stepping motor and gear train, together with time setting stem, are assembled piece by piece at the time the overall movement is assembled.
Watches have also been proposed in combination with calculators, radio transmitters, radio receivers, thermometers, and many other electronic devices, some of which use elements in common with the elements of an electronic watch and all of which occupy space inside the case of the wrist instrument.
It would be desirable to provide a universal stepping motor/gear train module of minimum size which is preassembled and especially adapted for connection to other devices which are disposed inside the case of the wrist instrument.
It would also be desirable to provide such a universal module adapted to use different sizes of energy cells or to receive power from an external source. It would also be desirable to provide such a universal module with a manual crown for setting the hands and to provide that the hands be driven either by external or internal electronic impulses.
It would also be desirable to provide such a module which is easily adapted to a self-contained timekeeping quartz analog watch, to a combo watch, or to a analog indicator for time or another condition to be displayed.
Accordingly, one object of the present is to provide an improved universal stepping motor/gear train module of minimum size and with a minimum number of components.
Another object of the invention is to provide such a universal module which is preassembled and especially adapted to occupy only a portion of a case of a wrist instrument along with other electronic devices connected thereto.